中文摘要：

对25 MeV中子引起氘核破裂反应的中子-中子准自由散射和17.36 MeV中子引起氘核破裂反应的中子-中子末态相互作用进行了细致的研究。首先,以小于5%的不确定度,精确测量了25MeV中子-中子准自由散射出射的中子三重微分截面。实验数据用基于现实核子-核子势（CD-Bonn,Argonne!18,Nijm I和II）的理论计算配合Monte-Carlo模拟进行了分析。实验结果比基于CD-Bonn势的理论预言高（16.0±4.6）%,进一步证实了目前的理论在中子-中子准自由散射方面还无法准确描述实验数据。其次,通过运动学非完全测量,精确测量了17.36 MeV中子引起氘核破裂反应在0°角附近出射的质子能谱,用基于现实核子-核子势（CD-Bonn、Bonn-B和Nijm I）的理论计算以及Monte-Carlo模拟分析了所测得的质子能谱,确定了中子-中子散射长度ann=（-16.8±0.6）fm。

英文摘要：

The neutron-neutron （n-n） quasi-free scattering （QFS） at 25.0 MeV and n-n final state interac- tion （FSI） at 17.4 MeV in the nd breakup reaction were studied in this work. First, the absolute breakup cross section was measured with an accuracy of 〈5 % in the n-n QFS. The measured data was analyzed by Monte-Carlo simulation based on modern realistic N-N potentials （CD-Bonn, Argonne v18, Nijm I and II）. The measured data exceeds the theoretical prediction based on CD-Bonn by （16.0±4.6%）. Second, the proton emission spectrum around 0° was measured in the nd breakup reaction at 17.4 MeV with kine- matical incomplete setup. The data was analyzed by Monte-Carlo simulation based on CD-Bonn. The n-n scattering length determined in this work was ann= （--16. 8±0. 6） fm.